Re: Index not used with or condition

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От Antony Paul
Тема Re: Index not used with or condition
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Msg-id 2989532e0502070314402057cc@mail.gmail.com
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Ответ на Index not used with or condition  (Antony Paul <antonypaul24@gmail.com>)
Ответы Re: Index not used with or condition  ("Steinar H. Gunderson" <sgunderson@bigfoot.com>)
Re: Index not used with or condition  (Jan Poslusny <pajout@gingerall.cz>)
Список pgsql-performance
On more investigation I found that index scan is not used if the query
have a function in it like lower() and an index exist for lower()
column.

rgds
Antony Paul


On Mon, 7 Feb 2005 14:37:15 +0530, Antony Paul <antonypaul24@gmail.com> wrote:
> Hi all,
>     I am facing a strange problem when I run EXPLAIN against a table
> having more than 100000 records. The query have lot of OR conditions
> and when parts of the query is removed it is using index. To analyse
> it I created a table with a single column, inserted 100000
> records(random number) in it created index and run a query which
> returns 1 record which have no or condition and it was using index.  I
> added an OR conditon and is using sequential scan. I set the
> enable_seqscan to off. I ran the tests again and is using index scan.
>    So which one I have to use. Is this any bug in Explain.
>
> rgds
> Antony Paul.
>

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